In this paper, the weld of Q235 steel pipe with diameter of 60 mm and thickness of 4 mm is simulated and analyzed by MSC.Marc software.After modeling, applying material physical properties, setting TRIMMERS weld bead and welding path, and applying boundary conditions, the operation results are analyzed and processed by submitting the work.According to the simulation results, different joints are selected to Swim Hat study the thermal cycle process and temperature distribution of joints under different joints.